New Delhi -LRB- CNN -RRB- If there were an annual prize for the `` World 's Most Hopeful Economy , '' it would likely go to India . After years of disappointing returns , the world 's largest democracy rediscovered vigor in 2014 . Stocks rose by a third ; foreign investment grew by a quarter ; the economy at one stage expanded at its fastest pace in two years . Beyond economics , the public mood seemed to lift : There was new hope for a young and tech-savvy India , unburdened by the failures of the past .

One man dominated the headlines , peddling optimism : India 's new Prime Minister Narendra Modi . Modi has fashioned a role for himself not only as CEO of India Inc. but also as its global ambassador , with blockbuster speeches promoting India in New York , Tokyo and Sydney . He is also India 's brand manager , launching catchy campaigns such as `` Make in India , '' '' #MyCleanIndia '' and `` Digital India . ''

Modi has won a broad mandate , as evidenced by his party 's performance in tricky state elections in December . And yet , 2015 marks the end of Modi 's honeymoon . After all , hope can only go so far . Modi 's greatest accomplishment in 2014 was to offer promise : He energized weary Indians . He convinced the world that India had a giant `` open '' sign on its front doorstep -- almost literally , with visas on arrival . He spent much of the year in campaign mode , in India and abroad .

But in 2015 , Modi will need to transition from speechmaker to doer , or else risk disenchanting another generation .

That suggests 2015 will be a defining year for India .

Let 's start with economics . India was blessed with favorable tail winds last year . At the start of Modi 's term , Brent crude was trading at about $ 110 a barrel . By year-end , prices had halved . Cheaper oil was a boon to India 's economy : The deficit shrank , inflation fell , and perhaps most crucially , the government took the opportunity to end decades of subsidies and deregulated diesel . New taxes on oil look set to generate billions of dollars in excess revenue every year .

India 's government will look to use that money well . Can it deliver on its promises of clean water and power to 1.25 billion Indians ? Can it really improve India 's broken infrastructure -- ports , roads , trains and bridges , some of which never seem to connect ? Can it begin to fulfill its promise to put a toilet in every home ? Or has too much been promised ?

In any case , India needs much more money and investment , likely from abroad . And Modi will need another important currency : cooperation from his lawmakers . India needs to rid itself of arcane laws on retrospective taxation . It will look to unite its states under a common tax system to foster free trade and business . But these acts will take political will and wile . Can Modi legislate as well as he can campaign ? Can he really , as his government has promised , improve India 's ranking for doing business from a dismal 142nd in the world to somewhere in the top 50 ? These are all questions that Modi will need to answer in 2015 .

Foreign policy has come easily to Modi so far . He will begin 2015 basking in the glow of receiving President Barack Obama , the chief guest at India 's Republic Day , on January 26 . Obama will be the first sitting American president to visit India more than once . For Modi , however , good foreign policy means good business . He will look to strike deals not only with Obama , but with many other world leaders in 2015 -- on energy , trade , defense and infrastructure partnerships .

All that sounds right up Modi 's alley . The great unknown is how he will respond to a major foreign policy crisis , the likes of which he largely escaped in 2014 . How will he react to a major skirmish with Pakistan ? How will he balance his desire to boost Chinese trade with fears about Beijing 's growing assertiveness in the region ? And what will he do if , in a big global crisis , he is pushed to choose sides between any of Russia , China and the United States ? Can India remain everyone 's friend ? Will Modi develop a values-based vision of India 's place in the world ?

On domestic issues , a year ago , Modi was known outside India mostly for his inability -- or worse , apathy -- in stopping one of the worst religious riots in modern Indian history , when some 2,000 Muslims were killed in Gujarat , the state he ran at the time . Modi 's perceived role led to his U.S. visa being revoked . A year on , New York City received Modi as if he were a rock star . In the space of a year , Modi has managed to transform his image abroad from pariah to visionary leader . Recent events are cause for renewed worry . Reports of Hindu groups forcing Christians and Muslims to `` convert '' to Hinduism threaten the very basis of the Indian secular state . Minorities simply can not live in fear . In 2015 , Modi will need not only to be a voice of reason , but he will also have to rein in radical fringe elements of his Hindu support base .

The safety of women will remain a major issue of concern at home and abroad . At his 2014 Independence Day speech , Modi remarked how the Indian people 's heads `` hang in shame '' with each report of rape . The sad reality is that Modi will probably make the same comment at this year 's speech . As I 've written previously , India has let its women down for centuries : They rank 134th in the world for economic opportunities , 126th for education and 141st for health . How can that be good enough for a country that aspires to be a major world power ?

Beyond politics , from living and reporting in India , I am hopeful about this country 's future . My optimism is based less on politics or economics , and more on a larger trend : the country 's technology boom . While the West has evolved in its Internet use -- from dial-up to cable to mobile 4G -- India 's journey has been different . It has jumped straight to a mobile revolution . Most Indians who discover the Internet will discover it on a cheap smartphone , not a PC . The pace of technology adoption , coupled with faster and cheaper hardware , will transform India in ways we are only just beginning to comprehend .

So , expect India to start leapfrogging many of the problems the West has spent decades dealing with : India has never had a real database of its citizens , but soon it will be the first country to have an entirely digital biometric ID system . There will be real changes in people 's lives and their economies with the help of e-commerce and apps for health , education , banking and transport . Beyond oil , politics or demographics , the biggest tail wind for India lies in its adoption of technology .

This will be India 's real revolution , and it is already underway .

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Ravi Agrawal : India needs much more money and investment , likely from abroad

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The great unknown is how Prime Minister will respond to foreign policy crisis , he says